Nut for fixing and electric instrument and fixing means of the same

ABSTRACT

A fastening nut for electric instruments in which a nut of metal is set into one end of a cylinder of synthetic resin in such a manner that its screw hole is exposed in the center of the said cylinder and wherein the other end of the cylinder is equipped with a parallel cut slit. The device is mated with a bolt which is passed through the electric instrument panel and the slit of the said nut is positioned in a fixing groove or rail of the instrument board to secure the instrument thereto.

United States Patent 1 [1 1 Hasegawa [451 Oct. 16, 1973 NUT FOR FIXING AND ELECTRIC INSTRUMENT AND FIXING MEANS OF THE SAME [76] lnventor: Kenichi Hasegawa, 10904,

Kohunbun-cho, lchikawa-shi, Chiba-ken, Japan [22] Filed: Sept. 28, 1971 [21] Appl. No.: 184,533

[30] Foreign Application Priority Data Oct. 7, 1970 Japan 45/99644 Dec. 24. 1970 Japan 45/140407 May 31. 1971 Japan 46/44957 [52] U.S. Cl. 1s1/41.7, 85/70 [51] Int. Cl. Fl6b 13/06, F16b 39/00 [58] Field of Search l'51/41.7, 41.75,

151/4176, 69, 68, 7, 41.74; 85/32 R, 32 K, 35, 70, 1 H; 287/189.36 F; 248/27, 361, 298, 25; 339/125 R, 22 R, 22 B [56] References Cited UNITED STATES PATENTS 2,836,216 5/1958 Rapata 151/4175 3,014,563 12/1961 Bratton .Q. 85/70 X 3,181,585 5/1965 Brewington l5l/41.75 3,444,917 5/1969 Bennett l51/41.7 3,449,774 6/1969 Wilham 85/70 X 3,489,312 1/1970 Hunckler et a1. 85/70 X 3,622,194 11/1971 Bryk 151/417 X Primary Exami'nerRam'on S. Britts Att0rneyE. F. Wenderoth et a1.

[57] ABSTRACT A fastening nut for electric instruments in which a nut of metal is set into one end of a cylinder of synthetic resin in such a manner that its screw hole is exposed in the center ofthe said cylinder and wherein the other 5 end of the cylinder is equipped with a parallel cut slit.

The device is" mated with a bolt which is passed I through the electric instrument panel and the slit of v the said nut is positioned in a fixing groove or rail of the instrument board to secure the instrument thereto.

4 Claims, 22 Drawing Figures PATENTEDUCT 18 I973 sum 1 or d FIG.5

R.. m m V m ATTORNEYS PMENTEDHCT 16 ms 3765;464 sum 2 or 4 KENICHI HASEGAWA,

IN VENT OR BYLDMMMaKQM ATTORNEYS PMENTEDnm 16 ms 3755454 sum 3 nr 4 3 12 -5 FIG.

I i= 9 15 4 g A FIG.18 5

KENICHI HASEGAWA 9 H Y lbmo h dl INVENTOR ATTORNEYS I NUT FOR FIXING AND ELECTRIC INSTRUMENT AND FIXING MEANS OF THE SAME BACKGROUND OF THE INVENTION The present invention is designed to facilitate the operation of mounting or removing an electric instrument on or from an instrument board by means of a bolt or a screw even when the rear of the said board is inaccessable. A conventional method of fixing an electric instrument on a board such as a switchboard comprises the steps of first perforating a predetermined hole for fixing the instrument on the board and then cutting threads into the hole into which a bolt is fitted for securing the instrument.

This method usually requires a relatively considerable amount of time and labor for mounting the instrument, which corresponds to fifty percent of the entire labor for installing the switchboard. According to the conventional method, furthermore, a number of improvements must be made in respect to the inconveniences that the thickness of an instrument board being equipped with a screw hole thereon should be sufficient to allow several threads for the hole; that unless such sufficient thickness exists, the board can be deformed or damaged when a bolt is fitted thereinto, resulting in a failure to secure the instrument; and that another hole must be made as the reuse of the old hole is impossible when instruments are changed. In order to eliminate the aformentioned inconveniences, therefore, the invention allows for the securing of the electric instrument on a board regardless of the thickness thereof as well as providing a faster method of fixing the instrument by mating a nut of metal set into one end ofa synthetic resin cylinder with a bolt, the said end being easily fitted into a fixing groove or rail provided for a board such as a switchboard. According to the invention, furthermore, it is possible to securely mount an electric instrument on a board because the width of the slit is deformed to correspond to the thickness the board, the deformation being brought on the said slit wall by fitting the said slit into the fixing groove or rail and mating a bolt or a screw with the nut.

The wall of the said slit, which is buckled, is inclined to suffer an irregular deformation depending on the thickness thereof, but this irregularity can easily be rectified by making one side of the slit thinner.

As for a board for fixing an electric instrument, it may be equipped with a fixing groove but it is much easier to fit a fixing rail into the said board, in which case various intervals where instruments of different types and dimensions are placed are optional. Some types of instruments require tighter clamping of the bolt when fixed on a board and in such cases plates of metal may be placed into the board as washers.

BRIEF SUMMARY OF THE INVENTION This invention relates to a fastening nut and device in which a nut of metal is firmly embedded into one end of a cylinder of synthetic resin in such a manner that its screw hole is exposed from a center hole of the said cyl-- inder and parallel slits are provided on the other end of the cylinder. The said slits, being formed slightly wider than the thickness of an instrument board or that ofa fixing rail fixed on the board, can easily be slid into the groove or rail. With the cut slit of the" nut being fitted into the groove or rail of the board and with a bolt or a screw inserted through the fixing wall of the instrument being mated with the said metal nut, the instrument wall is clamped by means of the metal nut and the bolt head leading to its secure fixation.

Mating the bolt or screw and the metal nut, as described above, brings the latter nearer to the former along the thread pitches, thereby causing the cylinder incorporating the invented nut to deform the cut slit thereof. This causes the side wall of the slit to closely contact the groove or the sliding wall of the rail which holds the contact from sliding to secure the instrument.

As such deformation of the slit becomes difficult depending on the thickness and material used for the cylinder wall, it is necessary to provide a ring-like thin part on one side of the slit. When parallel slits alone are provided, the entire wall of the slits will be deformed and this makes the side wall of the slits closely contact the groove or rail resulting in an irregular deformation. To avoid this irregular deformation, the slits are provided with thinner portions. In this way, the slits will not be deforemed irregularly because of the existence of the thinner portions which alone suffer such deformation.

With the increased size or weight of electric instruments, they require a greater tightening of a bolt causing a danger of irregularily deforming or damaging a collar of the cylinder incorporating the invented nut and also a danger of softening the synthetic resin as the temperature rises which results in unsecure mounting of the instrument.

This invention allows the said cylinder to endure any powerful clamp or rise in temperature by means of a metal washer put into the said or flange portion of the cylinder whenever needed. In summary, it is an object of the invention to facilitate the operation of fixing or removing an electric instrument from the front of an instrument board even where it is impossible to reach the rear of the board. Another object is to enable the instrument to be fixed on the board without the need for making any screw holes therein. A further object is to securely mount the instrument on the board by bringing about a deformation of the slit portions when a bolt or a screw is tightened to the metal nut.

A still further object is to deform only the thin part of the slit when'tightening the bolt, the thin part being furnished on one side of the slit. A more specific object is to permit a secure mounting of the instrument on the board by means of a metal nut and a metal washer set into a cylinder of synthetic resin, even when the cylindrical piece receives a strong tightening the bolt and even as the temperature rises.

BRIEF DESCRIPTION OF THE DRAWINGS:

FIG. 1 is a front view of a nut equipped with opposite slits.

FIG. 2 is a side view of a section of the same as shown in FIG. 1.

FIG. 3 is a sectional view of the same as shown in FIG. 2 along the line A A.

FIG. 4 is a sectional view of the same in use.

FIG. 5 is a front view of a nut equipped with a thin part on the opposite slits. FIG.6 is a side view of a section of the same as shown in FIG. 5.

FIG. 7 is a sectional view of the same as shown in FIG. 6 along the line B B.

FIG. 8 is a sectional view of the same in use.

FIG. 9 is a side view of the same as shown in FIG. 8.

FIG. is an oblique view of the nut shown in FIG. 9

FIG. 11 is a front view of an additional embodiment of the invention.

FIG. 12 is a side view of a portion of the same as shown in FIG. 11.

FIG. 13 is a sectional view of the same as shown in FIG. 12 along the line C C.

FIG. 14 is a sectional view of the same as shown in FIG. 12 along the line D D.

FIG. 15 is a sectional view of the same in use.

FIG. 16 is a base view of a sectional portion of the same.

FIG. 17 is an oblique view of a washer of the same.

FIG. 18 is a front view of the same as shown in FIG.

17 in use.

FIG. 19 is a front view of an electric instrument that is fixed on a groove of a board by means of a nut of the invention.

FIG. 20 is a side view of the same as shown in FIG. 19.

FIG. 21 is a front view of an electric instrument that is fitted into the rail of a board by means of a nut of this invention.

FIG. 22 is a side view of the same as shown in FIG. 21.

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a fastening nut for fixing an electric instrument to a board comprising a nut of .metal which is embedded into one end of a cylinder of with the slit of the said nut being fitted into a fixinggroove or rail on the instrument board.

It is desirable to use materials for the cylindrical piece having a strong nature and electrically insulated quality, as well as proper elasticity and'hardness.

Nylon or polypropylene, for example, is most suitable but vinyl chloride or other synthetic resins may be used. The instrument board of this invention, for which conventional switchboards or other metal boards may be used, does not require sufficient thickness for making a screw hole thereon, as it involves no direct perforation for the bolts.

The invention will now be described by way of embodiments thereof, as follows:

FIGS. 1 to 4 show an example of a fastening nut being equipped with no thin part on its slits. According to't'his embodiment, a nut of metal 4 is firmly embedded into the end of a thick nylon cylinder 1 so that the screw hole is exposed in the center hole 3, of the said cylinder 1. The other end of the cylinder 1 is equipped with parallel slits 6 which are so cut as to provide a width S1 slightly greater than the thickness S of the instrument board 5. The width 1, between the slits 6 is slightly smaller than the width 1 of the groove 7 on the board 5. The slits 6 are also cut to provide side walls formed substantially deeper than the outer wall of the metal nut 4.

FIGS. 5 to 10 show another example of the slit 6 shown in FIGS. 1 to 4, one side of which is equipped with a thin part 8, the other constituent elements being the same as in the previous example. According to this example, the sectional shape of the thin part becomes a little thicker around the four corners thereof as shown in the parallel oblique lines of FIG. 7, but this raises no problems in use.

However, it is also possible to obtain the sectional shape as shown in the dotted'lines 8a of FIG. 7.

FIGS. 11 to 18 show still another embodiment of the fastening nut which is used where a particularly greater clamping is required and where high temperatures may occur. According to this embodiment, a nut of metal 4 is firmly embedded into one end ofa thick nylon cylinder 1 in such a manner that its screw hole 2 is exposed at the center hole 3 of the cylinder. The other end of the cylinder being equipped with a metal washer 9 positioned parallel to the end of the metal nut 4 while the side wall of thesaid nylon cylinder is equipped with parellel slits 6 in such a manner that the inner ends of the metal nut 4 and of thewasher 9 are exposed.

The width and depth of the slit are the same as provided in each of the two previous examples. In other words, the positions where the metal nut 4 and the washer 9 are to be placed should be decided after considering the width of the slits 6. An electric instrument 10 can be fixed on the board 5 by means of the fastening nut, by inserting from the front of the board the slit side of the nylon cylinder 1 into a round hole 11 furnished at an end of the groove 7. The slits 6 are then fitted into the groove 7 while moving the cylinder laterally, thereby preventing the said cylinder from being removed. I

The wall of the instrument is tightly fixed to the board sliding the cylinder to a predetermined position, making the rear wall 12 of the instrument contact the end 13a of the flange 13 exposed in the front of the board 5 into which the cylinder 1 is inserted, and then inserting a screw or bolt 14 into the wall 12. The end of the screw is mated with the metal nut 4, and the bolt is then tightened, squeezing the side walls of the slits 6, thereby working as if a nylon packing were interposed.

The nut used in the example of FIG. 5 permits a more secure mounting since the thinner portions 8 are deformed under further bolt tightening pressure with the device used in the example of FIG. 11, there is no danger whatever of damaging any part of the device even when receiving a stronger clamping force or of creating an unsecure connection even at high temperature, since a metal washer is interposed between the board and the rear wall and the inner surface 4a of the metal nut 4 is brought directly in contact with the rear of the board. In this embodiment, the metal washer 16, the rear wall 12, the metal washer 9 and the fixing board 5 are placed between the head 15 of a bolt 14 and the metal nut 4.

' When using a board having rails 17 as shown in FIGS. 21 and 22, there is no need for grooves 7, and it is possible to fit the nut into parallel rails which are properly spaced and fixed on the board.

In manufacturing quantities of switchboards comprising instruments of the same dimensions placed in their convenient particularly for spot installations where the instruments to be mounted are of different types or dimensions.

An effect of the invention is to facilitate the mount ing or removing operation of an electric instrument on or from a board the rear of which cannot be reached by hand. This invention further reduces the amount of labor and time required for the installation of an instrument and virtually eliminates any limitations of the thickness of the board since there is no need for cutting screw holes in the board. Furthermore, the invention eliminates the danger of damaging or breaking any part of the device even when receiving a powerful clamping force and results in a secure connection even at high temperatures since a metal nut and metal washer are fitted at predetermined positions.

The fastening device of the invention provides a means by which the positions of the instruments to be mounted can be easily adjusted, the instruments can be individually mounted or removed and the fastening nuts can be easily exchanged. In addition, since a cylindrical piece of synthetic resin having the metal nut embedded is used, it can assure the electrical insulation thereof.

What l claim is:

l. Fastening means for mounting an electric instrument on an instrument board comprising a cylindrical member of synthetic resin having a metal nut firmly embedded into one end thereof, said nut being positioned near said one end exposing its threaded hole from the center hole of saidcylindrical member, said cylindrical member having parallel slits adjacent the other end thereof, and a flange member at said other end, said parallel slits forming a section having a width slightly greater than the thickness of said instrument board, the distance between said slits being substantially less than the outer diameter of said embedded metal nut, the outer wall of said cylindrical member adjacent said slits being substantially thinner throughout its circumference than the remaining sections of said cylindrical member'whereby said thinner portion is deformable under bolt tightening pressure.

2. Fastening means for mounting an electric instrument on an instrument board as claimed in claim 1 wherein the inner end of said embedded metal nut is exposed at one end of said parallel slits, said flange member having a metal washer attached thereto, said metalwasher being exposed at the other end of said slits, whereby the exposed portions of said embedded metal nut and said metal washer are brought into contact with the walls of the instrument board under bolt tightening pressure.

3. Fastening means for mounting an electric instrument on an instrument board as claimed in claim 1 wherein said fastening means further includes a groove in said instrument board, the parallel slits of said cylindrical member being positioned in said groove and a bolt passing through said instrument and said board and being screwed into said nut embedded in said cylindrical member.

4. Fastening means for mounting an electric instrument on an instrument board as claimed in claim 1 wherein said fastening means further includes a rail mounted on said instrument board, the parallel slits of said cylindrical member being positioned in said rail and a bolt passing through said instrument and said rail and being screwed into said nut embedded in said cylindrical member. 

1. Fastening means for mounting an electric instrument on an instrument board comprising a cylindrical member of synthetic resin having a metal nut firmly embedded into one end thereof, said nut being positioned near said one end exposing its threaded hole from the cenTer hole of said cylindrical member, said cylindrical member having parallel slits adjacent the other end thereof, and a flange member at said other end, said parallel slits forming a section having a width slightly greater than the thickness of said instrument board, the distance between said slits being substantially less than the outer diameter of said embedded metal nut, the outer wall of said cylindrical member adjacent said slits being substantially thinner throughout its circumference than the remaining sections of said cylindrical member whereby said thinner portion is deformable under bolt tightening pressure.
 2. Fastening means for mounting an electric instrument on an instrument board as claimed in claim 1 wherein the inner end of said embedded metal nut is exposed at one end of said parallel slits, said flange member having a metal washer attached thereto, said metal washer being exposed at the other end of said slits, whereby the exposed portions of said embedded metal nut and said metal washer are brought into contact with the walls of the instrument board under bolt tightening pressure.
 3. Fastening means for mounting an electric instrument on an instrument board as claimed in claim 11 wherein said fastening means further includes a groove in said instrument board, the parallel slits of said cylindrical member being positioned in said groove and a bolt passing through said instrument and said board and being screwed into said nut embedded in said cylindrical member.
 4. Fastening means for mounting an electric instrument on an instrument board as claimed in claim 1 wherein said fastening means further includes a rail mounted on said instrument board, the parallel slits of said cylindrical member being positioned in said rail and a bolt passing through said instrument and said rail and being screwed into said nut embedded in said cylindrical member. 